class Parent (object):
	def parent_method(self):
		print 'calling parent method'
		
class Parent2 (object):
	def parent2_method(self):
		print 'calling parent2 method'
		
class Child (Parent):
	def child_method(self):
		print 'calling child method'

p = Parent()
p.parent_method()

c = Child()
c.child_method()
c.parent_method()
print c.__class__
print Child.__bases__

print

Child.__bases__ = (Parent2,)
print Child.__bases__
c2 = Child()
c2.parent2_method()